title: Myostatin preferentially down-regulates the expression of fast 2x myosin heavy chain in cattle.
abstract: Myostatin is involved in an inhibitor of muscular growth and differentiation. Myoblasts derived from double-muscled Japanese shorthorn cattle (DM myoblasts) with absence of functional myostatin had higher abilities to proliferate and differentiate than myoblasts derived from normal-muscled cattle (NM myoblasts). In DM myoblasts, mRNA expressions of fetal myosin heavy chain (MyHC) in growth medium and of fast 2a and 2x MyHC in fusion medium were significantly greater than that in NM myoblasts. No significant difference existed in expressions of embryonic and slow MyHC mRNA between DM and NM myoblasts. The expression of MyoD mRNA was suppressed in myoblasts by administration of myostatin. Two cloned DM myoblast strains (DMc) were established. Addition of myostatin for DMc resulted in less myotube formation and suppression of mRNA expression of fast 2x MyHC. These findings suggest that the endogenous myostatin preferentially down-regulates the expression of the fast 2x MyHC and participates in differentiation of myofiber types during early bovine myogenesis.
authors.affiliation: Laboratory of Functional Morphology, Department of Animal Biology, Graduate School of Agricultural Science, Tohoku University, Miyagi, Japan.
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Hayashi
authors.forename: Masato
authors.initials: M
authors.lastname: Miyake
authors.forename: Kouichi
authors.initials: K
authors.lastname: Watanabe
authors.forename: Hisashi
authors.initials: H
authors.lastname: Aso
authors.forename: Seigo
authors.initials: S
authors.lastname: Hayashi
authors.forename: Shyuichi
authors.initials: S
authors.lastname: Ohwada
authors.forename: Takahiro
authors.initials: T
authors.lastname: Yamaguchi
mesh_terms: D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D015536:Down-Regulation / Q000502:physiology*; D018482:Muscle, Skeletal / Q000166:cytology / Q000502:physiology; D018995:Myosin Heavy Chains / Q000235:genetics*; D055435:Myostatin; D012333:RNA, Messenger / Q000235:genetics; D016212:Transforming Growth Factor beta / Q000502:physiology*
chemical_list: D055435:Myostatin; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; D018995:Myosin Heavy Chains